Orthogonality catastrophe due to local electron correlation, Prog

We discuss the orthogonality catastrophe between the ground states of the unperturbed and perturbed Fermi systems clue to local electron correlation U in the Anderson model. \Ve show that the symmetric Anderson model presents a special case in which no catastrophe appears and that in the asymmetric case the catastrophe results from the self-energy shift. Anderson 1l discovered the orthogonality theorem m the Fermi gas due to one-electron local scattering potential that the ground state of the total Fermi system perturbed by the potential of arbitrary strength is always orthogonal to that of the unperturbed one. This orthogonality catastrophe has played an essen